Rolls of toilet-paper, kitchen rolls or rolls of cleaning material for large consumer purposes are usually produced by rolling the paper on a thin tube-shaped core, usually a sleeve of cardboard. This cardboard sleeve usually adds extra cost to the production of paper-rolls and, in addition, it is left over when the paper has been consumed and must be discarded.
Paper-rolls without cores where the paper is drawn out from the centre of the roll are known earlier from for instance SE-B-399 694. To avoid collapse of the hole at the centre according to this publication it is proposed that the innermost paper turns are fixed to each other by means of water having optionally an addition of a binder. In this manner, a reinforcing core is made from the innermost turns which, however, are not completely glued to each other and can be rolled off together with the rest of the paper strip and used as the rest thereof. The winding of the paper strip occurs on an expandable winding shaft which after the winding, is contracted so that it can easily be removed from the thus formed paper-roll.
One example of an expandable winding shaft of said kind is shown in EP-A-0 408 246.
From SE-B-455 367 a coreless toilet paper-roll is known from which the paper can be rolled off from the periphery of the roll. The winding shaft has a relatively small diameter, approximately 10-15 mm, and has a polygonal or a cog wheel resembling section form, whereby the centre hole, which is formed when the paper strip is wound on the shaft and this has been removed, will have alternating radially outwardly directed pressure grooves and inwardly arched parts. The winding shaft is solid, that means not expandable, and its corners or cogs can possibly be helically shaped along the shaft to describe a good vicious circle and to avoid noise during the winding up on a so called supporting roller machine. Due to its small diameter the shaft can be removed without substantial problems from the paper-roll after the winding has terminated.